135440542134421 has 2 divisors, whose sum is σ = 135440542134422. Its totient is φ = 135440542134420.

The previous prime is 135440542134419. The next prime is 135440542134427. The reversal of 135440542134421 is 124431245044531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 116256483772900 + 19184058361521 = 10782230^2 + 4379961^2 .

It is a cyclic number.

It is not a de Polignac number, because 135440542134421 - 2¹ = 135440542134419 is a prime.

Together with 135440542134419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135440542134427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67720271067210 + 67720271067211.

It is an arithmetic number, because the mean of its divisors is an integer number (67720271067211).

Almost surely, 2^{135440542134421} is an apocalyptic number.

It is an amenable number.

135440542134421 is a deficient number, since it is larger than the sum of its proper divisors (1).

135440542134421 is an equidigital number, since it uses as much as digits as its factorization.

135440542134421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 921600, while the sum is 43.

Adding to 135440542134421 its reverse (124431245044531), we get a palindrome (259871787178952).

The spelling of 135440542134421 in words is "one hundred thirty-five trillion, four hundred forty billion, five hundred forty-two million, one hundred thirty-four thousand, four hundred twenty-one".